A hydrogen peroxide biosensor based on the bioelectrocatalysis of hemoglobin incorporated in a kieselgubr film

An unmediated hydrogen peroxide biosensor was prepared by co-immobilizing hemoglobin (Hb) with kieselgubr at a pyrolytic graphite electrode surface. Hb exhibited direct electrochemistry in the film, as well as peroxidase-like activity. This modified electrode showed high stability, catalytic activity towards the reduction of hydrogen peroxide. A linear dependence of the catalytic current on the concentration of hydrogen peroxide was observed in the concentration range of 5.0×10 −6 to 3.0×10 −4 mol/l with a detection limit of 2.1×10 −6 mol/l. The apparent Michaelis-Menten constant ( K M app) was estimated to be 975 μmol/l.